Bank cards have electronic chips for transaction security. The EMV standard was created by Europay, MasterCard and Visa, the initials of which relate to the definition of an interoperability and security standard between smart bank cards. For a card to have EMV certification, it must have a chip, which is itself certified and has a contact type interface according to the standard ISO 7816 and/or a contactless interface according to the standard ISO 14443. To limit the risks of hacking, EMV chips do not have any other communication interface.
Besides, the making of smart cards with a screen and one or more pushbuttons to communicate with the cardholder is also known. These cards are not currently widespread and are used for generating single-use passwords for computer transactions. Such cards generally have a chip with a contact or contactless smart card communication interface and a communication port designed for communication with other integrated circuits such as for example an I2C communication interface or General Purpose Input/Output (GPIO) ports. It is thus possible for a smart card microcontroller to communicate with a display controller that controls a liquid crystal display or a so-called “electronic ink” display.
One idea would be to make a bank card with a screen to display the latest transactions completed. That raises a problem if the smart card is to be made according to the EMV standard. These chips do not have an additional input/output port for such an application, and for security reasons, the addition of other input/output ports is not preferable.
As a result, it is not possible to steer the display from an EMV chip. A solution is thus required to be able to display the latest transactions completed on a smart card.